The present invention relates to a vacuum cleaner.
More particularly, the invention relates to a vacuum cleaner of the type having replaceable filter (i.e., dust) bags.
Still more specifically, the invention relates to a vacuum cleaner having an indicator which informs a user of the extent to which the filter bag is filled with dust and the like.
Vacuum cleaners with filling-condition indicators are already known. In these the carrier plate to which the replaceable filter bag is secured, has two openings of which one communicates with the suction intake of the vacuum cleaner. The paper of the filter bag extends across the other opening and is interposed between the same and a conduit leading to the pressure-responsive filling-condition indicator. This has two inherent disadvantages: a proper seal between the open end of the conduit and the filter paper of the dust bag is difficult to establish so that ambient air may be drawn into the line and lead to incorrect filling-condition indications, and the open end of the conduit must be in exact registry with the carrier-plate opening which requires considerable precision (and attendant costs) in the manufacture of the parts involved.